<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>flex</title>
</head>
<body>
    <style>
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        .nav {
            width: 100%;
            height: 50px;
            background-color: rgb(60, 60, 60);
            color: white;
            text-align: center;
            line-height: 50px;
            font-size: 20px;
        }

        .container {
            width: 100%;
            height: 1000px;
            background-color: grey;
            display: flex;
            justify-content: center;
            align-items: center;
        }

        .container .left, .container .right {
            width: 15%;
            height: 100%;
            background-color: rgb(158, 251, 141);

            font-size: 20px;
            line-height: 1000px;
            text-align: center;
        }


        .container .content {
            width: 70%;
            height: 100%;
            background-color: white;

            font-size: 20px;
            line-height: 1000px;
            text-align: center;
        }

        .footer {
            width: 100%;
            height: 150px;
            background-color: rgb(60, 60, 60);
            color: aqua;
            
            font-size: 20px;
            text-align: center;
            line-height: 150px;

        }
    </style>

    <div class="nav">
        导航栏
    </div>

    <div class="container">
        <div class="left">
            左侧边栏
        </div>
        <div class="content">
            内容区域
        </div>
        <div class="right">
            右侧边栏
        </div>
    </div>

    <div class="footer">
        页脚
    </div>
</body>
</html>